Coolant Temp Sensor??? - LS1LT1 Forum : LT1, LS1, Camaro, Firebird, Trans Am, Engine Tech Forums

1fast84 · 01-26-2010, 03:22 PM

I have a 93 T/A with and lt1. So it's speed density and has an ecm. The car wont idle until it warms up and the fans run at al times. I was thinkin a bad coolant temp sensor? Anybody else had this problem?

shoebox · 01-26-2010, 05:02 PM

Is the SES on? Why not flash the code(s) if it is.

1fast84 · 01-26-2010, 08:11 PM

No the ses light is not on. I have a scanner.

LT1MonteSS · 01-26-2010, 08:15 PM

Quote:

Originally Posted by 1fast84

No the ses light is not on. I have a scanner.

Monitor coolant temp with the scanner.

1fast84 · 01-26-2010, 09:20 PM

Yeah i will tomorrow i was just tryin to get some ideas while i was at work thanks tho

shoebox · 01-27-2010, 07:13 AM

Quote:

Originally Posted by 1fast84

No the ses light is not on. I have a scanner.

Why are the fans on all the time, if the SES is not on? Does the SES light work?

1fast84 · 01-27-2010, 12:08 PM

Quote:

Originally Posted by shoebox

Why are the fans on all the time, if the SES is not on?
I dunno i was hopin somebody could tell me.

Does the SES light work?

Yes i unplugged the coolant temp sensor just to see what would happen and the ses light came on but nothin else changed

2fast4u88 · 01-28-2010, 01:16 PM

Why is the fans staying on then? If the ses light works and is off at the time they run all the time?

1fast84 · 01-28-2010, 04:15 PM

In dunno so i unplugged them since it's been so cold they didn't need to be on. Now they won't come on at all. I looked at my scanner and when i let the car warm up it said they should have been on and now they won't work. My temp gauge is going crazy too. It goes way up past 260 then back down to 220. I scanned it when it was past 260 and my temp sensor said it was onlt 212? I think i'm just gonna put a mechanical temp gauge and a manual switch for the fans.

1fast84 · 01-28-2010, 05:34 PM

And the other thing is when the car is cold it should idle higher and it doesn't. It wants to try and idle at 600 but it'll keep stalling out until it warms up. Any ideas on that?

LT1MonteSS · 01-28-2010, 06:39 PM

Have you checked and cleaned the iacv.Does it hold idle if you open the blades a little.If yes then your iacv is sticking.

1fast84 · 01-28-2010, 07:16 PM

It idles as soon as it warms up just doesn't idle the first 5 mins

2fast4u88 · 01-28-2010, 10:02 PM

Ok when my supercharger belt broke and took out the water pump temp sensor. When I started the car. The temp gauge would go up past 220. Then the check gauge engine light came on and it started working like normal. Maybe also look at the wire going to the sensor in the head where the gauge gets its reading. Maybe the wire is agianst the header.

As for the fans have you tried a new relay? Maybe try that. If that doesn't work check the wiring to the fans. As for the idle problem that sounds like the iac valve. From either it sticking or going bad. Or possible the tb out of adjustment. What does the iac count look like when it does this? Then when it warms up?

1fast84 · 01-28-2010, 10:07 PM

I checked the wire for the gauge it seemed fine. I might try a new sending unit see if that fixes the prob. I'll scan it when it wont idle and when it will idle and see what it's looks like. I'm doin the intake gaskets this weekend so i'll clean the whole tb out and see if that helps too.

2fast4u88 · 01-28-2010, 10:13 PM

You running a stock tb? If not I bet it is the tb then. Also check the tps voltage real quick while you mess with it.

As for the sensor it could be that. The one in the water pump runs the computer/fan if I remember right. Then the one in the head goes to the gauge. Though not sure why my temp gauge went on the blitz when it was the water pump on that broke.

O to clean the tb. I like the seafoam spray. It works pretty good. Though carb cleaner should work. As long as you do get it on any sensors some how. Or into where the tb should be oiled/greased.